commit 02cafcc1bf6e2968c2efdf459871167970da150e
author egdaniel <egdaniel@google.com> Mon Jul 21 11:37:28 2014 -0700
committer Commit bot <commit-bot@chromium.org> Mon Jul 21 11:37:28 2014 -0700
tree 6407fddf603d832732c775e450c6430e0d120e55
parent 5b7c7c4ed3baf24e10db8f1b647f7c711b4420fd

Remove gpu shader optimatization for solid white or trans black colors

Running test on the added bench which draws a grid of all white paths, all blue paths, or alternating checkered white/blue paths.

With optimization in (ms):
         White       Blue        Checkered
Linux    ~80         ~80         ~160
N7       ~800        ~1100       ~1500
Moto-e   ~830        ~1100       ~2500

Without optimization in (ms):
         White       Blue        Checkered
Linux    ~80         ~80         ~80
N7       ~1100       ~1100       ~1100
Moto-e   ~1100       ~1100       ~1500

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/5f78d2251a440443c9eaa321dad058d7a32bfef7

R=bsalomon@google.com

Author: egdaniel@google.com

Review URL: https://codereview.chromium.org/375823005

src/gpu/gl/GrGLProgramDesc.cpp

diff --git a/src/gpu/gl/GrGLProgramDesc.cpp b/src/gpu/gl/GrGLProgramDesc.cpp
index 27a1fab..e1a3191 100644
--- a/src/gpu/gl/GrGLProgramDesc.cpp
+++ b/src/gpu/gl/GrGLProgramDesc.cpp
@@ -66,6 +66,7 @@
 
     bool skipColor = SkToBool(blendOpts & (GrDrawState::kEmitTransBlack_BlendOptFlag |
                                            GrDrawState::kEmitCoverage_BlendOptFlag));
+
     int firstEffectiveColorStage = 0;
     bool inputColorIsUsed = true;
     if (!skipColor) {
@@ -99,11 +100,6 @@
     bool requiresLocalCoordAttrib = !(skipCoverage  && skipColor) &&
                                     drawState.hasLocalCoordAttribute();
 
-    bool colorIsTransBlack = SkToBool(blendOpts & GrDrawState::kEmitTransBlack_BlendOptFlag);
-    bool colorIsSolidWhite = (blendOpts & GrDrawState::kEmitCoverage_BlendOptFlag) ||
-                             (!requiresColorAttrib && 0xffffffff == drawState.getColor()) ||
-                             (!inputColorIsUsed);
-
     bool readsDst = false;
     bool readFragPosition = false;
     // We use vertexshader-less shader programs only when drawing paths.
@@ -192,11 +188,7 @@
 #endif
     bool defaultToUniformInputs = GR_GL_NO_CONSTANT_ATTRIBUTES || gpu->caps()->pathRenderingSupport();
 
-    if (colorIsTransBlack) {
-        header->fColorInput = kTransBlack_ColorInput;
-    } else if (colorIsSolidWhite) {
-        header->fColorInput = kSolidWhite_ColorInput;
-    } else if (defaultToUniformInputs && !requiresColorAttrib) {
+    if (defaultToUniformInputs && !requiresColorAttrib && inputColorIsUsed) {
         header->fColorInput = kUniform_ColorInput;
     } else {
         header->fColorInput = kAttribute_ColorInput;
@@ -205,11 +197,9 @@
 
     bool covIsSolidWhite = !requiresCoverageAttrib && 0xffffffff == drawState.getCoverageColor();
 
-    if (skipCoverage) {
-        header->fCoverageInput = kTransBlack_ColorInput;
-    } else if (covIsSolidWhite || !inputCoverageIsUsed) {
+    if ((covIsSolidWhite || !inputCoverageIsUsed) && !skipCoverage) {
         header->fCoverageInput = kSolidWhite_ColorInput;
-    } else if (defaultToUniformInputs && !requiresCoverageAttrib) {
+    } else if (defaultToUniformInputs && !requiresCoverageAttrib && inputCoverageIsUsed) {
         header->fCoverageInput = kUniform_ColorInput;
     } else {
         header->fCoverageInput = kAttribute_ColorInput;